Ventilating system



W. L. FLEISHER VENTILATING SYSTEM Filed May 20, 1927 INV BY Q Q ew? Patented May 22, 1928.

UNITED STATES PATENT OFFICE.

WALTER L. FLEISHER, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO

AUDITORIUM VENTILA'IING CORPORATION, OF JERSEY CITY, NEW JERSEY, A COR- PORATION OF NEW JERSEY.

VENTILATING SYSTEM.

Application filed May 20,

This invention relates to air conditioning apparatus and more particularly to systems intended to maintain desirable conditions within a public enclosure. In the ventilation of buildings it has been found that the comfort of the occupants is dependent not only upon the temperature, humidity, and purity of the air, but also upon air movement, this latter playing its part not only in its direct effect upon the occupants, but also in its services in maintaining a proper dis tribution of suitable air throughout the enclosure.

It is also desirable that there shall not be too great a difference in temperature between incoming air and the air in the room itself.

The problem of ventilating public enclosures, particularly theatres, is primarily a cooling and de-humidifying one, both winter and summer. In the winter time the natural dry outside air assists in this, but in the summer time the effect is opposite; in either instance, the outer air may differ very widely, both in temperature and moisture content from that desired in the room.

On the other hand, the air within the room, with an automatic system of control, is fairly constant, in both respects, and is quite close to the condition desired. Great economies may be thus effected by utilizing, insofar as possible, air coming from the room itself rather than outside air. This withdrawn or recirculated air is preferably used for two purposes. First, because of its close approximation to the standard desired, it may be used in part at least,as the air to be conditioned intensively to restore the room conditions. Second, it may be used to increase the volume of circulating air and to dilute the intensively conditioned air so that it shall not differ too much either in temperature or humidity from the standa 'd to be maintained.

It is an object of the present invention to provide a system which will accurately control and maintain the predetermined conditions within the room and which will employ a minimum of power and which will operate satisfactorily under widely varying conditions of outside air and in spite of wide changes of heat and moisture given off within the room.

Fora fuller understanding of the nature and objects of the invention, referer'ice Russuw should be had to the following detailed description taken in connection with the accompanying drawing, which is a diagrammatic representation of a system embodying important features of my invention.

In the drawings the numeral 1 represents a room or building to be ventilated, having diagrammatically represented at 2 the customary windows and doors. Suitable outlets and inlets 3 and 4 are provided, and means are provided for withdrawing air from the outlets and back in through the inlets. In practice there will be, generally, a plurality of both inlets and outlets, properly distributed throughout the building and it is to be 1927. Serial No. 192,898.

understood in the present invention, that a proper and suitable distribution will be em ployed. Only one inlet and one outlet have been shown in the drawing, as the specific distribution does not form a part of this invention.

Where a conditioning problem is primarily a dehumidifying one, and the dehiunidification is to be effected by refrigeration, itis more economical intensively to dehumidify a small body of air than extract the same quantity of moisture from a larger body. Moreover, .the effect of refrigeration can be most efliciently produced upon air within the temperature.limits involved inventilation, by bringing such bodiesof air into direct contact in the form of a spray. The particular embodiment of the invention herein illustrated, therefore, embraces this principle of dehumidification.

Thus, as shown, conditioning apparatus comprises,-generally, a washer 5, connected with heaters 6 and 7, and mixing chambers 8 and 9. The term conditioning apparatus will be used herein to refer to the washing apparatus, as it is well understood that the washer not only purifies the air, but isalso used to dry or humidity the air, dependent upon the temperature of the wash water employed and the condition of the air to be I washed. The exhaust air from the outlet 3 is carried by' a conduit 10 having two branches,- one of which, 11, leads to the mix-- i-ng chamber 8 atone side of the conditioning apparatus, while the other branch 12 leads to the other' mixing chamber 9 at the other side of the conditioning apparatus. The mixing chambers 8 and 9 are in direct communication with the conditioning apparatus cuit or by-pass around the washing apparatus. A damper 15 is arranged to contmol the passage of air through this short circuit and thus to determine the proportion which the conditioned air bears to the withdrawn air with which it is diluted, thus determining what proportion of the circulated air shall be treated. Means are provided for admitting fresh air to the system, comprising a fresh air inlet 16 in communication with the mixing chamber 8.

The above system is particularly appli- -cable to a plenum ventilation, that is, to a ventilation system in which the air within the building is maintained at, slightly greater pressure than the outside air, inorder that any filtration through cracks in the building or around the windows may be outward and thus without annoyance to the occupants. And thus while special exhausts may be provided, if desired, it will generally be found, with the ordinary building construction, the air lost to the system through such filtration when added to the air forcibly exhausted from smokin rooms and toilet rooms, is sufficient to afior ample air renewal without the necessity of pro viding special conduits for the discharge of air from the system. Thus the fresh 'air'ad mitted from the conduit 16 willobviously replace the air discharged from the system in this manner. A damper 17 in the fresh air conduit 16 controls the inlet-of fresh air and hence indirectly controls the quantity of air which is discharged from the system by controlling the relation between the pressure within the room and the outside pressure. A corresponding damper 111 in the' conduit 11 may be used to reduce the guantity of recirculated air through the conitioning' apparatus, whenever required. Thus, by closing the damper 17 when .desirable, the system may be used as a completely closed system, using and re-using, over and over, the same air, this being feasible because of the fact that the conditioning system automatically controls the humidity and removes impurities. on the other hand,

if the damper 17 be opened fully, a large quantity of fresh air will be admitted to the system. A blower 116 may beprovidedgin t e freshair intake to still further increase the fresh'air admitted to the system. incase plenum within the enclosure. Ordinarily it is desirable to circulate throu h the room about three parts of recirculate air to each part of fresh air, as in this. manner. a satis-* factory circulation may be maintained without undue cost for conditioningoutside air.

The conditioning apparatus in the form illustrated comprises, generally,a plurality of sprays 19, through which water is forced .by a pump 20. Provision is made whereby the water for the sprays may either be withdrawn from the spray chamber'through a conduit 21 for recirculatiomor may tained from a refrigerated source 22. A valve 23 is arranged to change the connection from the one to the-other. humidity by subjecting air to cooling reduces the air to a dew .point temperature generally below that required for ventilation. Some means should be provided, therefore, to raise the temperature above the dew point by adding a quantity of heat, which may conveniently bereferred to as superheat, and for controlling the quantlty of super-heat thus added. Since the returned air is generally above its dew point and therefore contains superheat, this may conveniently be done by controllin the quantity of returned air which is mixe'l with the conditioned air. however, the returned air will itself carry so much moisture as to render the latent heat out of proportion to the superheat, so

be ob- Control of Under many conditions,

that some additional means should be providcd for adding Superheat directly when required. The heater 7 will be employed whenever the air return is insufiicient to ever, to place it in the short-circuit duct 12.

admitting return air to the mixing chamber so that the air heated by it is thoroughly mingled with the conditioned air by passing through the fan.

The heater 6 within the fresh air conduit 16 tempers the incomiug'air, so that excessively cold air will not interfere with the conditioning operations. It is a character-; istic of a washing apparatus in-which all or a large proportion of the water is recir culated, that it reduces the air to the Wet bulb temperature of the incoming air. If,'fl for example, the incoming air has a dr bulb temperature of thirty-five and aliumi ity'of 50%, it will have a wet bulb temperature of 30 degrees. If this air be thenheated to '8tldegrees, dry bulb temperature, its wet bulb" temperature will be 52'"degrees instead of 30.;

form illustrated there is provided in the exhaust air conduit a wet' bulb thermostat 24 and a dry bulb thermostat 25, each controlling the flow of compressed air from a compressed, air source 26 into the control apparatus. The compressed air conduit 27 from the wet bulb thermostat 24 communicates with a diaphragm motor 28 for controlling the flow of steam from a source 29 I to the heater 6, and also through aconduit 30 to adiaphragm motor y31 for operating the valve 23. The compressed air conduit 32 from the dry bulb thermostat 25 communicates with a diaphragm motor 33 to control the flow of steam from source 29 to the heater 7, and also through the conduit 34.- to a diaphragm motor 35 to operate the damper 15 through a suitable link motion, the connections being such that at a rising wet bulb temperature the steam is cut off from the coil 6 and the circulation of the pump 20 changes from the recirculated water to the refrigerated water by operation of the valve 23. On a rising wet bulb temperature the steam coil within the conduit is shut off and the flow of air through the-- conduit is controlled.

In general, the system may be operated in two different ways. For example, the dry bulb thermostat may be arranged to control the superheat by controlling the valve 15, opening the valve to the extent of a quantity of superheat that is required, and the control of the steam supply through the motor 33 may be arranged to be brought into effect only when the superh'eat added by the return air proves insuflicient. Similarly the thermostat 24 and the motor 28 may be arranged to cut ofi the heater 6 at the valve 28 before moving the valve 23 to employ refrigerated water in the sprays. In general, in a system of this type, the heaters 6 and 7 will not be active during the summer months, so that during such months the superheat control is largely obta ned through the operation of the valve 15, and

'the moisture content by variation of the valve 23, the former varying the'proportions of return air which dilute the humidified air and the latter varying the dew point within the conditioning chamber.

In the foregoing system it will be clear that the conditionin maybe accomplished with the minimum 0 power, since the maximum quantity of air maybe by-passed without passing through" the r conditioning apparatus. At the same time; the heating is reduced to a ininimum,"siiice -the great bulk of the air .for ventilation is circulated through the s stem, thu s making: it unnecess saryto heat arge quantities of outside air or to raise the full volume of air from the dew poiiit to.tlie drybulb temperature de sired. Furthermore, the refrigeration of the cooling Waterv is required for 'only' a,

small... portion, of ,the airand hence the great bulk of the circulated'air does not need to be relieved of its superlieat only to x be reheated again.

It-will be seen, moreover, that the moisture content is directly controlled; by wet: bulb temperature controlof the conditioning ap-v paratus, while. the superheatrisdirectly controlled from the drybulb' temperature, and in so far as possible thef control is eflz'ected by controlling the proportion ofirecirculated air and the use of refrigerants, and heat is required'only when that control proves in;

adequate. It will thus be seen that a thorough and complete control of the-room conditions is obtained 'with a minimum of power. I

, The damper 17 and fan 116 may be autos niatically controlled to maintain a. predetermined pressure in the room if desired.

Since certain changes in carrying out the above process and in the constructions setforth, which embody the invention may be,

made without departing from its scope, i is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the in-- vention herein described, and all statements of the scope of the invention which, as 'a matter of language, might be saidfto fall therebetween.

Having described my claim as new and desire to secure by Letters Patent is: Q f 1.v The process'of ventilating. and conditioning a room, which ingludes withdrawing air from the room, mixing fresh air with withdrawn air, conditioningzsaid mixture, adding withdrawn air, having acondition different from the conditioned air to said invention, what. I'..

mixture after conditioning and adjusting l.

responsive to air conditions in, the roomitlze proportions of conditioned air and with? drawn air to vary the humidity in theroom;

2. The process of ventilating and condi tioning a room which includeswithdrawing air from the room, mixing fresh'airjwith withdrawn air, cond tioning said mixture,

adding withdrawn air having a condition different from the conditioned air to said mixture after conditioning and adjusting the proportions of conditioned air and witlr drawn air automatically to vary the humid ity in the room in accordance with the dry bulb ten'iperature of the air in the room.

3. The process of ventilating and conditioning a room, which includes withdrawing air from the room, mixing fresh air withwithdrawn air, bringing said mixture to a dew point and adjusting the tempera ture of the dew point in accordance with the wet bulb temperature in a room, mingling withdrawn air having a condition different from the conditioning air with said conditioned air in varying proportions and varying the proportions in accordance with the dry bulb ten'iperatm'e of the air in the room.

4.'The process of ventilating and conditioning a room which includes withdrawing air from the room, mixing fresh air with withdrawn air, bringing said mixture to a dew point and adjusting the temperature of .the dew point in accordance with the wet bulb tem erature in the room, minglingwithdrawn air aving a condition different from the conditioned air with said conditioned air in varying proportions and varying the proportions in accordance with the dry temperature of the air in the room and adding superheat before admitting said air to the room, and controlling said heat by the fall of the dry bulb temperature below a predetermined minimum.

5. The processof ventilating and conditioning a room which includes withdrawing air from the room, mixing freshair with withdrawn air, bringing said mixture toa dew point with variable temperature and adjusting the ten'iperature of the dew point in accordance with the wet bulb temperature in a room, mingling withdrawn air having a condition different from the conditioned air with said conditioned air in varying proportions and varying the proportions in accordance with the dry bulb temperature of the air in the room and heating the fresh air when the wet bulb temperature has fallen below a predetermined minimum.

6. In an apparatus for ventilating and conditioning a room, in combination, a conditionin apparatus, means for supplying water of a variable temperature to said conditioning apparatus, means for leading fresh air and air withdrawn from the room to said conditioning apparatus, a conduit for conductin air from the conditioning apparatus to t e room, a by-pass conduit for conducting air having a condition different from the conditioned air to said inlet conduit, means for heating'the fresh air admitted to the system, means for heating the exhaust air passing through said by-pass bulb conduit, means responsive to the wet bulb temperature arranged to respond to a rising wet bulb temperature to first cut off the heating of the fresh air and subsequently to lower the temperature of thecirculated water in the conditioning system and means responsive to the dry bull: temperature adapted, on rising dry bulb ten'iperature, first to cut off the heating o l the by-passed air and subsequently to reduce the air supply in the by-pass conduit.

7. A system for ventilating and conditioning a room comprising, in combination, a conditioning apparatus, means for controlling the temperature of the wash water fed to said apparatus to determine the dew point of the treated air, means for admitting fresh air and air withdrawn from the room to said conditioning apparatus, and means responsive to the wet bulb temperature of the withdrawn air for varying the temperature of the fresh air.

8. An apparatus for ventilating and conditioning a room comprising, in combination, an air conditionim apparatus, means for circulating air out of said room through said apparatus and into the room again, means for admitting fresh air to the system before passing through the conditioni 1g apparatus, means for diluting the conditioned air, means responsive to the wet bulb temperature for varying the moisture carried in by the conditioned air, and means responsive to the dry bulb temperature for varying the superheat carried in by the diluting air.

9. In an apparatus of the character described, in combination, means for conditioning air, means for admitting fresh air and air withdrawn from the room to the conditioning apparatus, means for diluting the conditioned air and means responsive to the dry bulb temperature for varying the superheat added to the air by such dilution adapted, on a falling dry bulb temperature, first to increase the quantity of such diluting air and subsequently, on further falling,

to increase the sensible heat thereof.

10. In an apparatus of the character described, in combination, a conditioning apparatus, means for admitting fresh and returned air to said conditioning apparatus, means for mingling withdrawn air with the conditioned air, means for admitting the mixture so formed to the building, means responsive to the wetbulb temperature for varying the quantity of latent heat in the mixture and means responsive to the dry bulb temperature for varying the quantity of superheat.

11. In an apparatus for. conditioning a room, in'combination, an air condition ng apparatus, means for feeding fresh air and air withdrawn from the room to the apparatus, and means for varying the dew point of the issuing air in accordance with the wet bulb temperature of the withdrawn air.

12. In an apparatus of the character described, in combination, means for feeding air to an enclosure, means for conditioning said air, means for supplying fresh air and return air for conditioning, means for diluting the conditioned air with recirculated air, and means responsive to the temperature within the room for varying the superheat carried in by the air entering the room.

13. In an apparatus of the character descr1bed,-1n combinat on, means for feedmg an to an enclosure, means for conditioning said air, means for supplying fresh air and] return air for conditioning, means for diluting the conditioned air with recirculated air, and means responsive to the tempera-' ture within the room for varying the quantity of such recirculated air.

14. In an apparatus of the character described, in combination, means for feeding air to an enclosure, means for conditioning said air, means for supplying fresh air and return air for conditioning, means for diluting the conditioned air with recirculated air, and means responsive to the' temperature of the room for varying the quantity of air returned for conditioning.

15. In an apparatus of the character described, in combination, means for feeding air to an enclosure, means for conditioning said air, means for supplying fresh air and air, and means responsive to the tempera-' ture of the room for varying the quantity of recirculated air used to dilute the conditioned air, and means responsive to the humidity of the room for varying the quantity of moisture carried in by the air entering the room.

17 The process of conditioning air in a room which includes withdrawing air therefrom, mixing fresh air with a part'of the withdrawn air, conditioning the mixture of withdrawn and fresh air, introducing unconditioned withdrawn air into the conditioned mixture, varying automatically the volume of such introduced air in accordance with the temperature of the room and discharging the complete mixture 1nto the room.

18. In a ventilating system conditionin apparatus,'an enclosure to be ventilate means for supplying fresh air and air from the enclosure to the apparatus, means for delivering said air, after conditioning, from the apparatus to the enclosure, means for mixing unconditioned air with said conditioned air prior to said delivery, and means for automatically regulating the proportions of conditioned and unconditioned air mixed, to obtain a desired condition of temperature and humidity.

19. In a ventilating system a conditioning device, an enclosure to be ventilated, aninlet to and an outlet from the conditioning device, first means for delivering air from the enclosure to the device to be conditioned and delivered at the outlet, second means for delivering air from the enclosure to a point adjacent the outlet to be mixed with the air delivered from the device, and means for automatically adjusting the dry and wet bulb temperatures of the mixture in accord-.

ance with desired conditions in the enclosure.

20. In a ventilating system a conditioning device, an enclosure to be ventilated,

ditioning a room comprising an.air conditioning device using a refrigerant for determining the dew point of treated air, means for admitting-fresh air and air withdrawn from the room to said conditioning device, and automatic means for-controlling the temperature of-the refrigerant used by the device. i

22. The process of ventilating a room which comprises saturating a mixture of return and fresh airhaving a certain temperature, varying the temperature in accordance with the wet bulb temperature of thereturned air, and automatically controlling the diluting of the mixture with returned air having a condition different from the mixture, to produce a desired dry bulb temperature.

In testimony whereof I affix my signature.

WALTER L. FLEISHER.

CERTIFICATE OF CCRRECTICN.

Patent N0. 1,670,656. Granted May 22, 1928, to

WALTER L. FLEISHER.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 4, line 16, claim 3, for the word "conditioning" read "conditioned"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 10th day of July, A. D. 1928.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

